The present invention relates to an image sensing system and control method thereof and, more particularly, to an image sensing system where a camera apparatus and a client device are connected, and a method of controlling the camera apparatus by the client device.
The assignee of the present invention has already developed an image sensing system, where a camera apparatus and a computer are connected via an RS serial cable or the like, for controlling an image sensing direction or zoom ratio of a camera apparatus by panning (rotate on a vertical axis) or tilting (rotate on a horizontal axis) the camera apparatus in accordance with a control command sent by a computer terminal. In such system, the computer includes software for operating a camera apparatus so that it is possible for an operator to operate the camera apparatus from the computer terminal by sending a control command by using a keyboard or mouse or the like.
In a case where the camera apparatus, connected to a computer terminal, includes functions for automatic focus (AF) and automatic exposure (AE), a control command related to AF or AE may be performed from the computer side.
In a case of utilizing a so-called electronic overhead projector (OHP) apparatus which senses an object (document or the like) placed on a platen, the focal point of the camera apparatus is adjusted so that the document placed on the platen is focused.
In the conventional image sensing system, however, the focal point and exposure are normally adjusted to focus the center of a sensing object. Therefore, in order to focus or adjust the exposure for an object which is not in the center of the sensing image, the camera apparatus must be panned or tilted to place the object of interest in the center of the sensing image. Such operation is cumbersome since the position of detection area of the camera apparatus must be adjusted.
Furthermore, in a case where a three-dimensional object is placed on the platen and sensed by the electronic OHP, the focal point must be manually adjusted to focus the portion subjected to image sensing.
Furthermore, there is an image sensing system which improves the quality of the sensed image by obtaining focus data and lightness data. In the image sensing system of this type, conventionally, an image is sensed by detecting a portion of signals of the image to control focusing.
However, in the conventional image sensing system, optical parameters set only for a portion of the image are applied to the entire image. Therefore, in a case where the image includes portions whose depth and lightness greatly vary, the sensed image of these portions are out of focus or exposure is not appropriate. Moreover, in a case where a wide angle image is sensed, a lens having a large field of view angle is generally used. In this case, a similar problem also occurs because the optical parameters are set based only on a part of the image.
The present invention is made in consideration of the above situation, and has as its object to provide an image sensing system for controlling a camera apparatus by utilizing a client device which is connected to the camera apparatus. More specifically, the present invention provides an image sensing system and control method thereof which enables the client device to quickly control camera parameters to perform image sensing of a desired area of an image and enables to quickly indicate the area where camera parameters are controlled.
According to the present invention, the foregoing object is attained by providing an image sensing system where a camera apparatus and a client device are connected for controlling the camera apparatus by the client device, comprising: image sensing means for sensing an object and obtaining an image signal thereof; detection area control means for controlling a detection area in the image signal; adjusting means for adjusting a camera parameter based on an image signal of the detection area; storage means for storing a shape and size of the detection area; display means for superimposing the detection area on an image obtained by the image sensing means after the adjusting means adjusts the camera parameter, based on the position, shape and size of the detection area; and shift instructing means for instructing the detection area control means to shift the detection area.
Since data related to the size and shape of detection area is stored in storage means in advance, the only information the shift instructing means needs to pass to the detection area control means is the amount of shift in the detection area. Accordingly, the adjusting means can quickly control the camera parameters based on the detection area, and display means can quickly indicate the detection area on the displayed sensed image.
It is another object of the present invention to provide an image sensing system and control method thereof which enables immediate focusing on a desired portion of an object, even in a case where a three- dimensional object is sensed.
According to an aspect of the present invention, the aforementioned camera apparatus is an electronic overhead projector (OHP) which senses an object placed on a platen.
By virtue of the above, an object placed on a platen can be immediately focused on each of the detection areas.
It is another object of the present invention to provide an image sensing system and method thereof which enables sensing an image where the camera parameters are optimized for the entire area of the image.
According to the present invention, the foregoing object is attained by providing an image sensing system where a camera apparatus and a client device are connected for controlling the camera apparatus by the client device, comprising: image sensing means for sensing an object and obtaining an image signal of the object; detecting means for detecting an image signal of a detection area in the obtained image signal; adjusting means for adjusting a camera parameter based on the image signal of the detection area; storage means for storing the image signal of the detection area sensed by the image sensing means after the adjusting means adjusts the camera parameter; shifting means for shifting the detection area; and image synthesizing means for synthesizing image signals of a plurality of detection areas stored in the storage means.
Accordingly, the present invention enables adjusting the camera parameters in unit of detection areas of an image which is sensed by the image sensing means and obtain a synthesized image by using the image synthesizing means.
It is another object of the present invention to provide an image sensing system and method thereof which controls differences of camera parameters in the synthesized image, which have been optimized by detection area units.
According to an aspect of the present invention, the storage means stores only image signals of an effective area in the detection area, and the image synthesizing means synthesizes images of a plurality of the effective areas stored in the storage means.
Accordingly, even if distances of focal points are extremely different in each of the detection areas, since very small effective areas in the detection areas are synthesized, differences of camera parameters in adjacent effective areas can be controlled.
It is another object of the present invention to provide an image sensing system and method thereof which can sense an omnidirectional image, and an image whose camera parameters are optimized in all areas of the image.
According to an aspect of the present invention, the aforementioned image sensing system further comprises direction control means for controlling an image sensing direction of the image sensing means, wherein the synthesizing means synthesizes images in unit of the image sensing direction controlled by the direction control means.
Accordingly, it is possible to obtain a synthesized image whose camera parameters are adjusted in each of the detection areas in an omnidirectional image.
The present invention is particularly advantageous since it enables reducing the amount of data in a command to shift the detection area. By virtue of this, camera parameter control in the detection area and displaying the detection area can be quickly performed.
Moreover, it is possible to sense an image where camera parameters are optimized in all areas of the image.
Other features and advantages of the present invention will be apparent from the following description taken in conjunction with the accompanying drawings, in which like reference characters designate the same or similar parts throughout the figures thereof.